INCREASED SEEDLING ESTABLISHMENT OF IMPATIENS WALLERANA IN RESPONSE TO LOW TEMPERATURE OR POLYETHYLENE GLYCOL SEED TREATMENTS

1980 ◽  
Vol 60 (2) ◽  
pp. 561-569 ◽  
Author(s):  
JOHN SIMMONDS

Seeds of Impatiens wallerana ’Elfin Scarlet’ were pre-treated with low temperature (8 °C) imbibition and hypertonic osmotic solutions of polyethylene glycol (PEG) 6000 in an attempt to improve seedling establishment under greenhouse conditions. Seeds held at 8 °C for 7 or 14 days germinated faster at 25 °C than non-treated seeds; seedling development was more rapid and there was a significant improvement in seedling establishment. Application of a soil cover improved seedling establishment in both control and pre-treated seeds. PEG pre-treated seeds germinated within 24 h of being released from osmotic control. The optimum pre-treatment was determined to be PEG −7.5 bars for 10 days, which resulted in 80% germination within 24 h, more advanced seedling development after 5 days, 92% seedling establishment and earlier flowering. Although PEG pre-treatments were superior to the low temperature pre-treatments, they are not readily applicable on a large scale. However, low temperature seed pre-treatment can be easily utilized to improve seedling establishment in commercial production.

2013 ◽  
Vol 52 (1-2) ◽  
pp. 121-137 ◽  
Author(s):  
G. Singh ◽  
S. S. Gill ◽  
Kamaljit K. Sandhu

Seeds of muskmelon (<em>Cucuniis melo</em>) cultivars viz Pb. Hybrid and Pb. Sunehri were osmoconditioned with Polyethylene glycol (PEG) and KNO<sub>3</sub> solutions to enhance their performance at low temperature. Osmoconditioning both with PEG 6000 and KNO<sub>3</sub> increased per cent germination, speed of germination, vigour in terms of dry weight and length of the seedlings and root/shoot ratios. KNO<sub>3</sub> priming recorded more pronounced effects in all the above mentioned parameters. Other vigour parameters such as electrical conductance of seed leachates was decreased with osmoconditioning whi]e dehydrogenase activity was enhanced. Osmoconditioning resulted in increased activity of amylases.


1986 ◽  
Vol 18 (9) ◽  
pp. 163-173
Author(s):  
R. Boll ◽  
R. Kayser

The Braunschweig wastewater land treatment system as the largest in Western Germany serves a population of about 270.000 and has an annual flow of around 22 Mio m3. The whole treatment process consists of three main components : a pre-treatment plant as an activated sludge process, a sprinkler irrigation area of 3.000 ha of farmland and an old sewage farm of 200 ha with surface flooding. This paper briefly summarizes the experiences with management and operation of the system, the treatment results with reference to environmental impact, development of agriculture and some financial aspects.


1994 ◽  
Vol 29 (12) ◽  
pp. 279-282 ◽  
Author(s):  
C. Güldner ◽  
W. Hegemann ◽  
N. Peschen ◽  
K. Sölter

The integration of the chemical precipitation unit which would inject a lime solution into a series of mechanical-biological processes, including nitrification/denitrification, and the sludge treatment are the subject of this project. The essential target is the large-scale reconstruction of a mechanical-biological sewage treatment plant with insufficient cleaning performance in the new German states and the adjustment of the precipitation stage to the unsteady inflow of sewage. First results indicate that the pre-treatment performance could be improved by ≅ 20% and the discharge of concentrations of COD, BOD, N and P could be reduced and homogenized. In addition, experiments on hydrolysis and acidifiability of the pre-treatment sludge have been carried out on a laboratory level with the object of making sources of carbon readily available for denitrification. In the course of the experiment, inhibition of fatty acid production by calcareous primary sludge could not be detected. The characteristics of the sludge, such as draining and thickening were considerably improved by the adding of lime.


Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 271
Author(s):  
Muhammad Imran ◽  
Asim Mahmood ◽  
Günter Neumann ◽  
Birte Boelt

Low temperature during germination hinders germination speed and early seedling development. Zn seed priming is a useful and cost-effective tool to improve germination rate and resistance to low temperature stress during germination and early seedling development. Spinach was tested to improve germination and seedling development with Zn seed priming under low temperature stress conditions. Zn priming increased seed Zn concentration up to 48 times. The multispectral imaging technique with VideometerLab was used as a non-destructive method to differentiate unprimed, water- and Zn-primed spinach seeds successfully. Localization of Zn in the seeds was studied using the 1,5-diphenyl thiocarbazone (DTZ) dying technique. Active translocation of primed Zn in the roots of young seedlings was detected with laser confocal microscopy. Zn priming of spinach seeds at 6 mM Zn showed a significant increase in germination rate and total germination under low temperature at 8 °C.


2021 ◽  
Vol 9 (6) ◽  
pp. 615
Author(s):  
Sophie Steinhagen ◽  
Swantje Enge ◽  
Karin Larsson ◽  
Joakim Olsson ◽  
Göran M. Nylund ◽  
...  

The growing world population demands an increase in sustainable resources for biorefining. The opening of new farm grounds and the cultivation of extractive species, such as marine seaweeds, increases worldwide, aiming to provide renewable biomass for food and non-food applications. The potential for European large-scale open ocean farming of the commercial green seaweed crop Ulva is not yet fully realized. Here we conducted manipulative cultivation experiments in order to investigate the effects of hatchery temperature (10 and 15 °C), nutrient addition (PES and 3xPES) and swarmer density (500 and 10,000 swarmers ml−1) on the biomass yield and biochemical composition (fatty acid, protein, carbohydrate, pigment and phenolic content) of off-shore cultivated Ulva fenestrata in a Swedish seafarm. High seedling densities were optimal for the growth of this northern hemisphere crop strain and significantly increased the mean biomass yield by ~84% compared to low seedling densities. Variations of nutrients or changes in temperature levels during the hatchery phase were not necessary to increase the subsequent growth in an open-water seafarm, however effects of the factors on the thallus habitus (thallus length/width) were observed. We found no significant effect of the environmental factors applied in the hatchery on the total fatty acid or crude protein content in the off-shore cultivated Ulva. However, low seedling density and low temperature increased the total carbohydrate content and furthermore, high temperature in combination with high nutrient levels decreased the pigment content (chlorophyll a, b, carotenoids). Low temperature in combination with high nutrient levels increased the phenolic content. Our study confirms the successful and sustainable potential for large-scale off-shore cultivation of the Scandinavian crop U. fenestrata. We conclude that high seedling density in the hatchery is most important for increasing the total biomass yield of sea-farmed U. fenestrata, and that changing temperature or addition of nutrients overall does not have a large effect on the biochemical composition. To summarize, our study contributes novel insights into the large-scale off-shore cultivation potential of northern hemisphere U. fenestrata and underpins suitable pre-treatments during the hatchery phase of seedlings to facilitate a successful and cost-efficient large-scale rope cultivation.


2020 ◽  
pp. 50384
Author(s):  
Allif Rosyidy Hilmi ◽  
Nibras Fuadi Muwwaqor ◽  
Nur Aini Fauziyah ◽  
Suminar Pratapa

2012 ◽  
Vol 490-495 ◽  
pp. 3211-3214 ◽  
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang

Synthesis reactions were carried out by chemical vapor deposition using iron catalyst supported on aluminum hydroxide at 400 °C and 420 °C, in the presence of argon as carrier gas and acetylene as carbon source. The aluminum hydroxide support was separated by refluxing the samples in 40% NaOH solution for 2 h and 36% HCl solution for 24 h, respectively. The samples were characterized by field-emission scanning electron microscopy, energy dispersive spectroscopy, high-resolution transmission electron microscopy and X-ray diffraction. The results show that carbon nanotubes were the main products at 420 °C, while large scale high purity nano onion-like fullerenes encapsulating Fe3C, with almost uniform sizes ranging from 10-50 nm, were obtained at the low temperature of 400 °C.


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